Ebook Donald school textbook of ultrasound in obstetrics and gynecology (3rd edition): Part 1

(BQ) Part 1 book Donald school textbook of ultrasound in obstetrics and gynecology presents the following contents: Safety of ultrasound in obstetrics and gynecology, development of 3D ultrasound, artifacts, pitfalls and normal variants, routine use of obstetric ultrasound, ultrasound markers of implantation,...

Donald School Textbook of Ultrasound in Obstetrics and Gynecology Donald School Textbook of Ultrasound in Obstetrics and Gynecology THIRD EDITION Editors Asim Kurjak MD PhD Professor and Chairman Department of Obstetrics and Gynecology Medical School University of Zagreb Sveti Duh Hospital Zagreb, Croatia Frank A Chervenak MD PhD Professor and Chairman Department of Obstetrics and Gynecology The New York Weill Hospital-Cornell Medical Center New York, USA ® JAYPEE BROTHERS MEDICAL PUBLISHERS (P) LTD New Delhi • Panama City • London Published by Jaypee Brothers Medical Publishers (P) Ltd Corporate Office 4838/24, Ansari Road, Daryaganj, New Delhi 110 002, India Phone: +91-11-43574357, Fax: +91-11-43574314 Website: www.jaypeebrothers.com Offices in India • Ahmedabad, e-mail: ahmedabad@jaypeebrothers.com • Bengaluru, e-mail: bangalore@jaypeebrothers.com • Chennai, e-mail: chennai@jaypeebrothers.com • Delhi, e-mail: jaypee@jaypeebrothers.com • Hyderabad, e-mail: hyderabad@jaypeebrothers.com • Kochi, e-mail: kochi@jaypeebrothers.com • Kolkata, e-mail: kolkata@jaypeebrothers.com • Lucknow, e-mail: lucknow@jaypeebrothers.com • Mumbai, e-mail: mumbai@jaypeebrothers.com • Nagpur, e-mail: nagpur@jaypeebrothers.com Overseas Offices • Central America Office, Panama City, Panama, Ph: 001-507-317-0160 e-mail: cservice@jphmedical.com, Website: www.jphmedical.com • Europe Office, UK, Ph: +44 (0) 2031708910 e-mail: info@jpmedpub.com Donald School Textbook of Ultrasound in Obstetrics and Gynecology © 2011, Jaypee Brothers Medical Publishers All rights reserved No part of this publication should be reproduced, stored in a retrieval system, or transmitted in any form or by any means: electronic, mechanical, photocopying, recording, or otherwise, without the prior written permission of the editors and the publisher This book has been published in good faith that the material provided by contributors is original Every effort is made to ensure accuracy of material, but the publisher, printer and editors will not be held responsible for any inadvertent error(s) In case of any dispute, all legal matters are to be settled under Delhi jurisdiction only First Edition: 2004 Second Edition: 2008 Third Edition: 2011 ISBN 978-93-5025-259-8 Typeset at JPBMP typesetting unit Printed in India To Ian Donald (Our Teacher and Friend) CONTRIBUTORS Badreldeen Ahmed Head Feto-Maternal Unit Department of Obstetrics and Gynecology Women’s Hospital Hamad Medical Corporation Doha, State of Qatar María J Barco Gynecologic Centre “Bolonia” Zaragoza, Spain Romina Castagno Hospital Vall d´ Hebron Barcelona, Spain Jill Beithon Ultrasound Services Sanford Health Fargo, ND, USA Gabriele Centini Prenatal Diagnosis Unit University of Siena Siena, Italy Juan Luis Alcázar Department of Obstetrics and Gynecology University Clinic of Navarra School of Medicine University of Navarra Pamplona, Spain Isaac Blickstein Department of Obstetrics and Gynecology Kaplan Medical Center Rehovot, and Hadassah-Hebrew University School of Medicine Jerusalem, Israel Giovanni Centini Prenatal Diagnosis Unit University of Siena Siena, Italy Tatjana Bozanovic School of Medicine Belgrade University, and Institute for Obstetrics and Gynecology Clinical Center of Serbia Belgrade, Serbia Stephen T Chasen Weill Medical College of Cornell University, New York, USA Cristian Andrei Department of Obstetrics and Gynecology Elias University Hospital Carol Davila University of Medicine Bucharest, Romania Aris Antsaklis Head 1st Department of Obstetrics and Gynaecology “Alexandra” Maternity Hospital University of Athens Medical School Athens, Greece Lluis Cabero Department of Obstetrics and Gynecology Hospital Vall d'Hebron Barcelona Spain Guillermo Azumendi Pérez Clinica Gutenberg Malaga, Spain José M Carrera Senior Member Department of Obstetric and Gynaecology University Institute Dexeus Autonomous University of Barcelona Barcelona, Spain Kazunori Baba Center for Maternal, Fetal and Neonatal Medicine Saitama Medical Center, Saitama Medical University Saitama, Japan Elena Carreras Fetal Medicine Unit Obstetrics and Gynecology Department Hospital Vall d’Hebron Barcelona, Spain Silvia Arevalo Fetal Medicine Unit Hospital Vall d’Hebron Barcelona, Spain Aleksandar Cetkovic Clinical Center of Serbia Belgrade, Serbia Frank A Chervenak Chairman Department of Obstetrics and Gynecology Joan and Sanford I Weill Medical College of Cornell University The New York Presbyterian Hospital, New York, USA Judith L Chervenak New York University School of Medicine New York, USA Carmina Comas Gabriel Fetal Medicine Unit Department of Obstetrics and Gynecology University Institute Dexeus Barcelona, Spain Antonella Cromi Department of Obstetrics and Gynecology University Medical School of Insubria, Varese, Italy viii Donald School Textbook of Ultrasound in Obstetrics and Gynecology Vincenzo D’Addario Department of Obstetrics and Gynecology, University of Bari Bari, Italy Luca Di Cagno Fetal Medicine Unit Department of Obstetrics and Gynecology, University of Bari Bari, Italy Edoardo Di Naro III Obstetrics and Gynecology Unit University Medical School of Bari Bari, Italy Marko Dosen Department of Reproductive Medicine and Gynecologic Endocrinology University Clinical Center Maribor Maribor, Slovenia Alaa Ebrashy Director Fetal Medicine Unit Kasr El Aini Hospital Faculty of Medicine Cairo University Cairo, Egypt A Kubilay Ertan Head Department of Obstetrics and Gynecology Hospital of Leverkusen Leverkusen, Germany Francesc Figueras Service of Fetal Medicine Clinical Institute of Gynecology Obstetrics and Neonatology University of Barcelona Barcelona, Spain Biserka Funduk Kurjak Department of Obstetrics and Gynecology Medical School University of Zagreb Zagreb, Croatia Alessandra Giocolano Department of Obstetrics and Gynecology III Obstetrics and Gynecology Unit University Medical School of Bari Bari, Italy Teresa Higueras Fetal Medicine Unit Hospital Vall d'Hebron Barcelona Spain Ulrich Honemeyer Head Department of Obstetrics and Gynecology Welcare Hospital Dubai, UAE Jon Hyett Head High Risk Obstetrics RPA Women and Babies Royal Prince Alfred Hospital Central Clinical School University of Sydney Sydney, Australia Shigenori Iwagaki Department of Maternal and Fetal Medicine National Hospital Organization Nagara Medical Center Nagara Gifu, Japan Robin B Kalish Division of Maternal-Fetal Medicine Department of Obstetrics and Gynecology Weill Medical College of Cornell University, New York, USA Ichiro Kawabata Department of Maternal and Fetal Medicine National Hospital Organization Nagara Medical Center Nagara Gifu, Japan Ashok Khurana The Ultrasound Lab New Delhi, India Sanja Kupesic Plavsic Department of Medical Education Paul L Foster School of Medicine Texas Tech University El Paso, Texas, USA Asim Kurjak Department of Obstetrics and Gynecology Medical School University of Zagreb Zagreb, Croatia Mario Lituania Centro di Fisiopatologia Preconcezionale e Prenatale Ospedali Galliera Genova Genova, Italy Aleksandar Ljubic School of Medicine University of Belgrade, and Institute for Obstetrics and Gynecology Clinical Center of Serbia Belgrade, Serbia Kazuo Maeda Department of Obstetrics and Gynecology (Professor Emeritus) Tottori University Medical School Yonago, Japan Jaideep Malhotra Malhotra Nursing and Maternity Home (P) Ltd Agra, India Narendra Malhotra Malhotra Nursing and Maternity Home (P) Ltd Agra, India Neharika Malhotra Malhotra Nursing and Maternity Home (P) Ltd Agra, India Alexandra Matias Department of Obstetrics and Gynecology Porto Medical Faculty of Medicine Hospital of S João Porto, Portugal Contributors Eva Meler Department of Obstetrics and Gynaecology University Institute Dexeus Autonomus University of Barcelona, Barcelona, Spain Luis T Mercé CENEGO (National Center of Gynecology and Obstetrics US) and Assisted Reproduction Unit International Ruber Hospital Madrid, Spain Eberhard Merz Chairman Department of Obstetrics and Gynecology Krankenhaus Nordwest Frankfurt/Main, Germany Srboljub Milicevic Institute for Obstetrics and Gynecology Clinical Center of Serbia Belgrade, Serbia Berivoj Miskovic Head Department of Obstetrics and Gynecology Clinical Hospital Sveti Duh Zagreb, Croatia Giovanni Monni Head Department of Obstetrics and Gynecology Prenatal and Preimplantation Genetic Diagnosis Microcitemico Hospital Cagliari, Sardinia, Italy Nuno Montenegro Porto Medical Faculty of Medicine Department of Obstetrics and Gynecology, Hospital of S João Porto, Portugal Ajlana Mulic-Lutvica Department of Women’s and Children’s Health Obstetrics and Gynaecology Uppsala University Uppsala, Sweden Zehra Nese Kavak Director Fetal Medicine Unit Department of Obstetrics and Gynecology Marmara University Teaching and Research Hospital, Pendik Istanbul, Turkey Agnieszka Nocun Gynecology and Oncology Clinic University Hospital in Krakow Krakow, Poland Aleksandra Novakov School of Medicine University of Novi Sad Clinical Center of Vojvodina Novi Sad, Serbia Zoltán Papp Maternity Private Clinic Semmelweis University Budapest, Hungary George A Partsinevelos 1st Department of Obstetrics and Gynaecology University of Athens Medical School Athens, Greece Bhargavi Patham Department of Medical Education Paul L Foster School of Medicine Texas Tech University El Paso, Texas, USA Vincenzo Pinto Department of Obstetrics and Gynecology University of Bari Bari, Italy ix Ritsuko K Pooh Director CRIFM Clinical Research Institute of Fetal Medicine PMC Osaka, Japan KyongHon Pooh Department of Neurosurgery Kagawa National Children’s Hospital, Zentsuji, Japan Maja Predojevic Department of Physiology Medical School University of Zagreb Zagreb, Croatia Luigi Raio Department of Obstetrics and Gynecology, University of Bern Bern, Switzerland Jai Prakash Rao Malhotra Nursing and Maternity Home (P) Ltd Agra, India Frederico Rocha Division of Maternal Fetal Medicine Department of OB/GYN and Women’s Health John A Burns School of Medicine University of Hawaii Honolulu, Hawaii, USA Carlota Rodó Fetal Medicine Unit Hospital Vall d'Hebron Barcelona, Spain Armando Pintucci Department of Obstetrics and Gynecology University of Bari Bari, Italy Lucia Rosignoli Prenatal Diagnosis Unit P Palagi Hospital Florence, Italy Branko M Plavsic Department of Radiology Paul L Foster School of Medicine Texas Tech University El Paso, Texas, USA Cristina A Rossi Fetal Medicine Unit Department of Obstetrics and Gynecology, University of Bari Bari, Italy x Donald School Textbook of Ultrasound in Obstetrics and Gynecology Aida Salihagic Kadic Department of Physiology, and Croatian Institute for Brain Research Medical School University of Zagreb Zagreb, Croatia Cihat en Chairman Department of Perinatology Cerrahpasa Medical School University of Istanbul Istanbul, Turkey Geeta Sharma Weill Medical College of Cornell University New York, USA Kohei Shiota Department of Anatomy and Developmental Biology and Congenital Anomaly Research Center Kyoto University Graduate School of Medicine Kyoto, Japan Daniel W Skupski Director Maternal-Fetal Medicine Associate Chairman Department of Obstetrics and Gynecology The New York Hospital of Queens Flushing, New York, USA Jiri Sonek Department of Obstetrics and Gynecology Wright State University President Fetal Medicine Foundation of the United States of America Dayton, Ohio, USA Yuichiro Takahashi Department of Maternal and Fetal Medicine National Hospital Organization Nagara Medical Center Nagara Gifu, Japan András Tankó Department of Obstetrics and Gynecology County Hospital Kecskemét, Hungary H Alper Tanriverdi Head Maternal-Fetal Medicine Unit Department of Obstetrics and Gynecology Adnan Menderes University Faculty of Medicine Aydin, Turkey Sakshi Tomar Malhotra Nursing and Maternity Home (P) Ltd Agra, India Nuria Toran Department of Pediatric Pathology Hospital Vall d'Hebron Barcelona Spain Zoltán Tóth Department of Obstetrics and Gynecology Debrecen University Debrecen, Hungary Boris Ujevic Department of Obstetrics and Gynecology Clinical Hospital Sveti Duh Zagreb, Croatia Martina Ujevic Polyclinic “Vili” Zagreb, Croatia Gino Varga Polyclinic “Nemetova” Zagreb, Croatia Oliver Vasilj Department of Obstetrics and Gynecology Clinical Hospital Sveti Duh Zagreb, Croatia Radu Vladareanu Chairman Department of Obstetrics and Gynecology Elias University Hospital Carol Davila University of Medicine Bucharest, Romania Veljko Vlaisavljevic Department of Reproductive Medicine and Gynecologic Endocrinology University Clinical Center Maribor Maribor, Slovenia Marcin Wiechec Obstetrics and Perinatology Clinic University Hospital in Krakow Krakow, Poland Tevfik Yoldemir Department of Obstetrics and Gynecology Marmara University Teaching and Research Hospital, Pendik Istanbul, Turkey Nadah B Zafar Department of Medical Education Paul L Foster School of Medicine Texas Tech University El Paso, Texas, USA Ivica Zalud Chief, Division of Maternal Fetal Medicine Department of OB/GYN and Women’s Health John A Burns School of Medicine University of Hawaii Honolulu, Hawaii, USA Mona Zvanca Department of Obstetrics and Gynecology Elias University Hospital Carol Davila University of Medicine Bucharest, Romania PREFACE TO THE THIRD EDITION The Ian Donald International School of Ultrasound bears testament to globalization in its most successful and worthwhile form The school was founded in Dubrovnik in 1981; in the preface of the first edition in 2004 we were proud to announce that the School had grown to branches Since then, the growth has been meteoric and now consists of 55 branches in almost every corner of the globe The reason for this success has been the tireless and selfless efforts of the world’s leading authorities in ultrasound who are willing to dedicate their valuable time without reimbursement to teach sonologists and sonographers throughout the world Our teachers put national, religious, political, and other parochial considerations aside as they strive to improve the care of all women and fetal patients Politicians in the countries represented by our School have much to learn from the purity of spirit that exists throughout our international family We believe that Ian Donald is smiling down from heaven at the School that bears his name In the educational efforts of the 55 branches of the Ian Donald School, there is clearly a need for a textbook to complement and supplement lectures and didactic sessions The first and second textbooks were successful in this endeavor, but with the explosion of knowledge, it was clear that an expanded and updated third edition would be invaluable For the sake of simplicity, our book is divided into three sections Section One deals with a variety of topics that lay the foundation for the rest of the book Section Two addresses the myriad subtopics in obstetric ultrasound that optimize the care of pregnant women and fetal patients The last section addresses the essential role that ultrasound plays in the many dimensions of clinical gynecology A special word of thanks to Jadranka, our tireless secretary for her hundreds of dedicated hours of quality work We are grateful to many course directors and lecturers of the Ian Donald School who have enabled its growth and have selflessly contributed to this volume In order to maximize the reach of this textbook by minimizing its price, all contributors have waived any honorarium or royalty Their dedication to the dream of globalized quality ultrasound has enabled its reality Asim Kurjak Frank A Chervenak CHAPTER 28 / Monochorionicity: Unveiling the Black Box 20 Blickstein I, Keith LG On the possible cause of monozygotic twinning: lessons from the 9-banded armadillo and from assisted reproduction Twin Res Hum Genetics 2007;10(2):394-9 21 Teplica D, Peekna K The mirror phenomenon in monozygotc twins In: Blickstein I, Keith LG (Eds) Multiple pregnancy, 2nd edition London, UK: Taylor and Francis; 2005 pp 277-88 22 Blokage CE Embryogenesis of chimeras, twins and anterior midlines asymmetries Human Reprod 2006;21:579-91 23 Oliviennes F Avoiding multiple pregnancies in ART double trouble: yes a twin pregnancy is an adverse outcome Hum Rep 2000;15:1663-5 24 Tummers P, De Sutter P, Dhont M Risk of spontaneous abortion in singleton and twin pregnancies after IVF/ICSI Hum Reprod 2003;18:1720-3 25 Zegers-Hochschild F, Bravo M, Fernandez E, et al Multiple gestation as a marker of reproductive efficacy: learning from assisted reproductive technologies Reprod Biomed Online 2003;8:125-9 26 La Sala GB, Nicoli A, Villani MT, et al Spontaneous embryonic loss rates in twin and singleton pregnancies after transfer of top- versus intermediate-quality embryos Fertil Steril 2005;84:1602-5 27 Matias A, Montenegro N, Blickstein I Sonographic evaluation of multiple pregnancies In: Kurjak A, Chevernak F (Eds) Textbook of Perinatal Medicine, 2nd edition New York: Informa Healthcare; 2006 pp 1591-3 28 Matias A, Oliveira C, da Silva JT, et al The effect of ICSI, maternal age, and embryonic stage on early clinical loss rate of twin versus singleton pregnancies Eur J Obstet Gynecol Reprod Biol 2006;130:212-5 29 Matias A, La Sala G, Blickstein I Early loss rates of the entire pregnancy are lower in singleton pregnancies following assisted reproduction Fert Steril 2007;88:1452-4 30 Lambers MJ, Mager E, Goutbeek J, et al Factors determining early pregnancy loss in singleton and multiple implantations Hum Reprod 2006;22(1):275-9 31 Bourthoumieu S, Yardin C, Terro F, et al Monozygotic twins concordant for blood karyotype, but phenotypically discordant: a case of “mosaic chimerism” Am J Med Genet A 2005;135(2):190-4 32 Cheng PJ, Shaw SW, Shih JC, et al Monozygotic twins discordant for monosomy 21 detected by first-trimester nuchal translucency screening Obstet Gynecol 2006;107(2 Pt 2):538-41 33 Hamasaki S, Shirabe S, Tsuda R, et al Discordant Gerstmann-Straussler-Scheinker disease in monozygotic twins Lancet 1998;24:1358-9 34 Bianchi DW Prenatal diagnosis: past, present, and future Prenat Diagn 2010;30(7):601-4 35 Machado AP, Ramalho C, Portugal R, et al Concordance for bilateral congenital diaphragmatic hernia in a monozygotic dichorionic twin pair - first clinical report Fetal Diagn Ther 2010;27(2):106-9 36 Gringras P, Chen W Mechanisms for differences in monozygous twins Early Hum Dev 2001;64(2):105-17 37 Derom C, Derom R The East Flanders Prospective Twin Survey In: Blicktein I, Keith LG (Eds) Multiple Pregnancy, 38 39 40 41 42 43 44 45 46 47a 47b 48 49 50 51 52 53 477 2nd edition London, UK: Taylor and Francis; 2005 pp 3947 Tong S, Vollenhoven B, Megher S Determining zygosity in early pregnancy by ultrasound Ultrasound Obstet Gynecol 2004;23:36-7 Sepulveda W, Sebire N, Hughes K, et al The lambda sign at 10-14 weeks of gestation as a predictor of chorionicity in twin pregnancies Ultrasound Obstet Gynecol 1996;7: 421-3 Wood SL, St Onge R, Connors G, et al Evaluation of the twin peak sign in determining chorionicity in multiple pregnancy Obstet Gynecol 1996;88:6-9 Pretorious D, Budorick N, Sciosia A, et al Twin pregnancies in the second trimester in an -fetoprotein screening program: sonographic evaluation and outcome Am J Roentgenol 1993;161:1007-13 Senat MV, Quarello E, Levaillant JM, et al Determining chorionicity in twin gestations: three-dimensional (3D) multiplanar sonographic measurement of intra-amniotic membrane thickness Ultrasound Obstet Gynecol 2006; 28(5):665-9 Blickstein I The twin-twin transfusion syndrome Obstet Gynecol 1990;76:714-22 Sepulveda W, Sebire N, Hughes K, et al Evolution of the lambda or twin-chorionic peak sign in dichorionic twin pregnancies Obstet Gynecol 1997;89:439-41 Blickstein I Monochorionicity in perspective Ultrasound Obstet Gynecol 2006;27:235-8 Linskens IH, Spreeuwenberg MD, Blankenstein MA, et al Early first-trimester free beta-hCG and PAPP-A serum distributions in monochorionic and dichorionic twins Prenat Diagn 2009;29(1):74-8 Matias A, Ramalho C, Montenegro N Search for hemodynamic compromise at 11-14 weeks in monochorionic twin pregnancy: is abnormal flow in the ductus venosus predictive of twin-twin transfusion syndrome? J Matern Fetal Neonatal Med 2005;18(2):79-86 Matias A, Montenegro N Down´s syndrome screening in multiple pregnancies Obst Gynecol Clin North Am 2005;32(1):81-96 Sebire NJ, Snidjers RJM, Hughes K, et al Screening for trisomy 21 in twin pregnancies by maternal age and fetal nuchal translucency thickness at 10-14 weeks of gestation Br J Obstet Gynecol 1996;103:999-1003 Cheng PJ, Huang SY, Shaw SW, et al Difference in nuchal translucency between monozygotic and dizygotic spontaneously conceived twins Prenat Diagn 2010;30(3):247-50 Cleary-Goldman J, Rebarber A, Krantz D, et al Firsttrimester screening with nasal bone in twins Am J Obstet Gynecol 2008;199(3):283.e1-3 Sepulveda W, Wong AE, Casasbuenas A Nuchal translucency and nasal bone in first-trimester ultrasound screening for aneuploidy in multiple pregnancies Ultrasound Obstet Gynecol 2009;33(2):152-6 Bush MC, Malone FD Down syndrome screening in twins Clin Perinatol 2005;32(2):373-86 Maymon R, Jauniaux E Down’s syndrome screening in pregnancies after assisted reproductive techniques: an update Reprod Biomed Online 2002;4(3):285-93 478 Section / Obstetrics 54 Gjerris AC, Loft A, Pinborg A, et al The effect of a ‘vanishing twin’ on biochemical and ultrasound first trimester screening markers for Down’s syndrome in pregnancies conceived by assisted reproductive technology Hum Reprod 2009;24(1):55-62 55 Goncé A, Borrell A, Fortuny A, et al First-trimester screening for trisomy 21 in twin pregnancy: does the addition of biochemistry make an improvement? Prenat Diagn 2005;25(12):1156-61 56 Spencer K, Salonen R, Muller F Down’s syndrome screening in multiple pregnancies using alpha-fetoprotein and free beta hCG Prenat Diagn 1994;14: 537-42 57 Spencer K, Kagan KO, Nicolaides KH Screening for trisomy 21 in twin pregnancies in the first trimester: an update of the impact of chorionicity on maternal serum markers Prenat Diagn 2008;28(1):49-52 58 Wald NJ, Rish S, Hackshaw AK Combining nuchal translucency and serum markers in prenatal screening for Down syndrome in twin pregnancies Prenat Diagn 2003;23(7):588-92 59 Nicolaides KH, Spencer K, Avgidou K, et al Multicenter study of first-trimester screening for trisomy 21 in 75 821 pregnancies: results and estimation of the potential impact of individual risk-orientated two-stage first-trimester screening Ultrasound Obstet Gynecol 2005;25(3):221-6 60 Madsen H, Ball S, Wright D, et al A re-assessment of biochemical marker distributions in T21 affected and unaffected twin pregnancies in the first trimester Ultrasound Obstet Gynecol 2010;37(1):38-47 61 Schatz F Clinical for the Physiology of the Fetus Berlin: Hirschwald; 1890 62 Bajoria R, Wigglesworth J, Fish NM Angioarchitecture of monochorionic placentas in relation to twin-to-twin transfusion syndrome Am J Obstet Gynecol 1995;172:85663 63 Lewi L, Cannie M, Blickstein I, et al Placental sharing, birthweight discordance, and vascular anastomoses in monochorionic diamniotic twin placentas Am J Obstet Gynecol 2007;197(6):587e.1-8 64 Mahieu-Caputo D, Muller F, Joly D, et al Pathogenesis of twin-twin transfusion syndrome: the renin-angiotensin system hypothesis Fetal Diagn Ther 2001;16(4):241-4 65 Danskin FH, Neilson JP Twin-to-twin transfusion syndrome: what are appropriate diagnostic criteria? Am J Obstet Gynecol 1989;161:365-9 66 Wenstrom KD, Tessen JA, Zlatnik FJ, et al Frequency, distribution and theoretical mechanisms of hematologic and weight discordance in MC twins Obstet Gynecol 1992;80:257-61 67 Wittmann BK, Baldwin VJ, Nichold B Antenatal diagnosis of twin-to-twin transfusion syndrome by ultrasound Obstet Gynecol 1981;58:123-7 68 Brennan JN, Diwan RV, Rosen MG, et al Fetofetal transfusion syndrome: prenatal ultrasonographic diagnosis Radiology 1982;143:535-6 69 Storlazzi E, Vintzileos AM, Campbell WA, et al Ultrasonic diagnosis of discordant fetal growth in twin gestations Obstet Gynecol 1987;69:363-7 70 Chescheir NC, Seeds JW Polyhydramnios and olygohydramnios in twin gestations Obstet Gynecol 1988;71:8824 71 Hecher K, Ville Y, Snijders R, et al Doppler studies of the fetal circulation in twin-to-twin transfusion syndrome Ultrasound Obstet Gynecol 1995;5:318-24 72 Zosmer N, Bajoria R, Weiner E, et al Clinical and echographic features of in utero cardiac dysfunction in the recipient twin-to-twin transfusion syndrome Br Heart J 1994;72:74-9 73 Van Mieghem T, Lewi L, Gucciardo L, et al The Fetal Heart in Twin-to-Twin Transfusion Syndrome, 2010 74 Fesslova V, Villa L, Nava S, et al Fetal and neonatal echocardiographic findings in twin-twin transfusion syndrome Am J Obstet Gynecol 1998;179:1056-62 75 Gardiner HM, Taylor MJ, Karatza A, et al Twin-twin transfusion syndrome: the influence of intrauterine laser photocoagulation on arterial distensibility in childhood Circulation 2003;107:1-6 76 Saunders NJ, Snijders RJ, Nicolaides KH Therapeutic amniocentesis in twin-twin transfusion syndrome appearing in the second trimester of pregnancy Am J Obstet Gynecol 1992;166:820-4 77 Sebire NJ, Souka A, Skentou H, et al Early prediction of severe twin-to-twin transfusion syndrome Human Reprod 2000;15:2008-10 78 Kagan O, Gazzoni A, Sepulveda-Gonzalez G, et al Discordance in nuchal translucency thickness in the prediction of severe twin-to-twin transfusion syndrome Ultrasound Obstet Gynecol (in press) 79 Lewi L, Lewi P, Diemert A, et al The role of ultrasound examination in the first trimester and at 16 weeks’ gestation to predict fetal complications in monochorionic diamniotic twin pregnancies Am J Obstet Gynecol 2008;199(5):493.e17 80 Montenegro N, Matias A, Areias JC, et al Increased nuchal translucency: possible involvement of early cardiac failure Ultrasound Obstet Gynecol 1997;10:265-8 81a Matias A, Montenegro N, Areias JC, et al Anomalous venous return associated with major chromosomopathies in the late first trimester of pregnancy Ultrasound Obstet Gynecol 1998;11:209-13 81b Matias A, Gomes C, Flack N, et al Screening of chromosomal defects at 11-14 weeks: the role of ductus venosus blood flow Ultrasound Obstet Gynecol 1998;12:380-4 82 Matias A, Huggon I, Areias JC, et al Cardiac defects in chromosomally normal fetuses with abnormal ductus venosus blood flow at 10-14 weeks Ultrasound Obstet Gynecol 1999;14:307-10 83 Matias A, Montenegro N, Areias JC Anticipating twin-twin transfusion syndrome in monochorionic twin pregnancy Is there a role for nuchal translucency and ductus venosus blood flow evaluation at 11-14 weeks? Twin Res 2000; 3(2):65-70 84 Matias A, Montenegro N, Loureiro T, et al Screening for twin-twin transfusion syndrome at 11-14 weeks of pregnancy: the key role of ductus venosus blood flow assessment Ultrasound Obstet Gynecol 2010;35(2):142-8 CHAPTER 28 / Monochorionicity: Unveiling the Black Box 85 Taylor MJ, Denbow ML, Tanawattanacharoen S, et al Doppler detection of arterio-arterial anastomoses in monochorionic twins: feasibility and clinical application Hum Reprod 2000;15:1632-6 86 Luke B, Minogue J, Witter FR The role of fetal growth restriction and gestational age on length of hospital stay in twin infants Obstet Gynecol 1993;81:949-53 87 Fraser D, PIcard R, Picard E, et al Birth weight discordance, intrauterine growth retardation and perinatal outcomes in twins J Reprod Med 1994;39:504-8 88 Blickstein I Normal and abnormal growth of multiples Semin Neonatol 2002;7:177-85 89 Blickstein I Is it normal for multiples to be smaller than singletons? Best Pract Res Clin Obstet Gynecol 2004;18:61323 90 Blickstein I Growth aberration in multiple pregnancy Obstet Gynecol 2005;32:39-54 91 Blicsktein I, Keith LG Neonatal mortality rates among growth-discordant twins, classified according to the birth weight of the smaller twin Am J Obstet Gynecol 2004;190:170-4 92 Luke B, Keith LG The contribution of singletons, twins and triplets to low birth weight, infant mortality and handicap in the United States J Reprod Med 1992;37:661-6 93 Matias A, Maiz N, Montenegro N, et al Ductus venosus flow at 11-13 weeks in the prediction of birthweight discordance in monochorionic twins J Perinat Med, 2011 (in press) 479 94 Pharoah P Neurological outcome in twins Semin Neonatol 2002;7:223-30 95a Pharoah P Risk of cerebral palsy in multiple pregnancies Clin Perinatol 2006a;33(2):301-13 95b Pharoah P Twins and locomotor disorder in children J Bone Joint Surg Br 2006b;88(3):295-7 96 Blickstein I Do multiple gestations raise the risk of cerebral palsy? Clin Perinatol 2004;31:395-408 97 Topp M, Huusom LD, Langhoff-Roos J, et al Multiple birth and cerebral palsy in Europe: a multicenter study Acta Obstet Gynecol Scand 2004;83:548-53 98 Yokoyama Y, Shimizu T, Haykawa K Prevalence of cerebral palsy in twins, triplets and quadruplets Int J Epidemiol 1995;24;24:943-8 99 Bejar R, Vigliocco G, Gramajo H, et al Antenatal origin of neurologic damage in newborn infants: multiple gestations Am J Obstet Gynecol 1990;162:1230-6 100 Malone FD Monochorionic pregnancy – Where have we been? Where are we going? Am J Obstet Gynecol 2003;189:1308-9 101 Lopriore E, Nagel HT, Vandenbussche FP, et al Longterm neurodevelopmental outcome in twin-to-twin transfusion syndrome Am J Obstet Gynecol 2003;189:1313-8 102 Senat MV, Loizeau S, Cooudere S, et al The value of middle cerebral artery peak systolic velocity in the diagnosis of fetal anemia after intrauterine death of one monochorionic twin Am J Obstet Gynecol 2003;189:1319-23 29 CHAPTER Ultrasonography and Birth Defects Narendra Malhotra, Jaideep Malhotra, Sakshi Tomar, Neharika Malhotra, JP Rao INTRODUCTION “Care Is Absolute, Prevention Is Ideal” Ultrasound has revolutionized obstetric practice all over the world and there is no doubt about it With good resolution machines, Color Doppler, 3D and 4D scanning it is now possible to make a prenatal diagnosis of many structural anomalies, which are lethal, life threatening and debilitating All pregnancies are at risk of producing fetal malformations or birth defects Some pregnant women are at a greater risk The world consensus on whether all pregnancies should be screened by ultrasound for anomalies and when, is still divided Birth defect is a global problem Birth defect is one of the leading causes of perinatal mortality and morbidity, accounting for 2–3% of all live-births.1 Presence of anomalies and their undesirable consequences for the affected neonate, family and medical fraternity is a very convincing argument by many experts on universal screening Regardless of whether a woman is in low risk (majority cases) or high risk category (genetic, diabetes, etc.) the risk of fetal malformation is always there and because there are no symptoms and these pregnancies may be uneventful It is estimated that every year 7.9 million children are born with a serious birth defects of genetic or partly genetic origin A further million are born with serious birth defects of postconception origin which result from environmental teratogens such as alcohol, rubella, syphilis and iodine deficiency which can either cause death or lifelong disability.1 While this problem has been addressed in the West, it is yet to be addressed in developing countries where 94% of those born with birth defects reside and where 95% of the children who die from birth defects are born.1 The prevalence of fetal malformations is 65% though only 2–2.5% are potentially life threatening, lethal or represent a major cosmetic defect1 (Fig 29.1) It is seen that incidence of aneuploidy (Trisomy 21) screen with maternal age (Fig 29.2) Ultrasound routine screening is a very valuable tool for detecting birth defects.2 In India, due to its high birth rate, population and consanguinity in certain communities, the burden of birth defects is significant This has been reported by the Federation of Obstetric and Gynecological Societies of India (FOGSI) birth defects registry (unpublished data) An estimated 495,000 infants with congenital malformations are born every year.2 In addition, 21,400 with Down’s syndrome, 9,000 with thalassemia, 5,200 with sickle cell anemia, 390,000 with G6PD deficiency and 9,760 with amino acid disorders are born every year.3 Diagnosis is generally late or ineffective and the infrastructure for management and rehabilitation of the families is not easily accessible This makes the burden of genetic diseases and birth defects particularly severe as compared to the western countries CHAPTER 29 / Ultrasonography and Birth Defects 481 Social stigma, discrimination, lost hopes and lack of opportunities add to the emotional and financial burdens To reduce the impact of birth defects, national health policy makers need to first recognize the prevalence, disability and burden of the disease Figure 29.1: Frequency of aneuploidies vs number of anomalies CAUSES The incidence of birth defects in USA is one out of 33 and may be much more in developing countries and the countries where no formal and structured registry exists There are three major categories of causes: Genetic Environmental Complex genetic/unknown Genetic Causes Chromosomal or single-gene disorders are known to account for about 25–30% of all birth defects Chromosomal abnormalities are seen in about 0.5% of live newborns Recently, use of ‘telomeric probes’ has increased this incidence further as about 5–7% of mentally challenged children have a cryptic translocation that cannot be detected by traditional cytogenetic methods A ‘mutation’ in the genetic locus can give rise of ‘single gene disorder’ Not all mutant genes manifest at birth or lead to structural problems Some birth defects are caused by errors in genes or chromosomes Those caused by genes can be inherited— passed by parents to their children Some inherited disorders are more common in certain ethnic groups, such as sickle cell disease, cystic fibrosis, and Tay–Sachs disease Figure 29.2: Incidence of aneuploidy (Trisomy 21) screen with maternal age Chromosomal defects are caused by missing, damaged or extra chromosomes These defects are often the result of an error that occurred when the egg and sperm were joining Common chromosomal disorders are Down syndrome and trisomy 18 Generally, the risk of having a baby with Down syndrome, trisomy 18, and other chromosomal disorders increases with advancing maternal age.3 Environmental Causes These causes account for 5–10% of birth defects These include nutritional deficiencies, maternal illnesses, teratogenic drugs or radiation and infectious agents However, the extent of the damage depends upon the timing of exposure and the individual’s genetic susceptibility Other birth defects result from the fetus being exposed to harmful agents, such as medications, chemicals, and infections Whether a woman or her baby is harmed depends on how much of the agent they have been exposed to, when during her pregnancy a woman is exposed to the agent and for how long Complex Genetic/Unknown Causes These comprise of about 65–70% of birth defects This may be caused by defects in more than one gene or a complex interaction of the environment and genes 482 Section / Obstetrics TABLE 29.1 TABLE 29.4 Clinical markers of high-risk pregnancy Non-sonographic findings Advanced maternal age Previous birth of a malformed fetus Family history of a malformed fetus Consanguinity Exposure to drugs/radiation Maternal diabetes mellitus Bad obstetric history Bleeding in early pregnancy Abnormal results from a CVS/amniocentesis Abnormal immunoglobulin profile Abnormal triple test/increased alfa fetoprotein/Abnormal pregnancy associated plasma protein (PAPP) Abnormal first-trimester Dual Marker test ULTRASOUND FOR CONGENITAL DEFECTS Sometimes, a mixture of factors is the cause For many birth defects, the exact cause is not known Thorough screening of all pregnant patients is impossible in the current scenario, but we can and should offer ultrasound to all possible pregnant women as a prenatal diagnostic test.4 Most of the birth defects can be identified and diagnosed in utero A careful history, proper biochemical screening and ultrasound added with invasive testing wherever required can pick up structural, chromosomal, metabolic abnormalities in the unborn An early diagnosis leads to good counseling and informed choice to the parents with option of termination Clinically high risk groups for a detailed anomalies scan are shown in Table 29.1 The sonographic findings which are indications for a detailed anomalies scan are listed in Tables 29.2 and 29.3 Nonsonographic laboratory investigations which can warrant a detailed anomalies scan are listed in Table 29.4 TABLE 29.2 Sonographic findings: First trimester Oligoamniotic sac Embryonic bradycardia Abnormal yolk sac Increased nuchal translucency One identified anomaly Dates size discrepancy at 9–12 weeks TABLE 29.3 Sonographic findings: Second and third trimester Increased nuchal translucency Symmetric IUGR Polyhydramnios Oligohydramnios Breech Presentation Twins One identified anomaly First Trimester Nuchal Translucency This prenatal test also called the NT or nuchal fold scan It assesses the baby’s risk of having Down’s syndrome (DS) and some other chromosomal abnormalities as well as major congenital heart problems The NT test uses ultrasound to measure the clear (translucent) space in the tissue at the back of developing baby’s neck Babies with abnormalities tend to accumulate more fluid at the back of their neck during the first trimester, causing this clear space to be larger than average The NT scan is done between 11 and 13 weeks It is offered along with blood test in what is known as first-trimester combined screening5 (Figs 29.3A to E) Pitfalls in measuring the nuchal translucency include the presence of an encephalocele, a nuchal cord, an amniotic band or a loose amnion that can be mistaken for the nuchal skin edge.5 It is therefore imperative to magnify the image It is sometimes helpful to wait for spontaneous fetal activity A cut off of mm was used in many studies as a threshold for an abnormal nuchal translucency, although recently it has become apparent that normal nuchal translucency thickens with increasing gestational age Other First-Trimester Signs of Aneuploidy Growth patterns of the crown-rump length have been evaluated to determine whether growth abnormalities could be utilized as signs of aneuploidy.6 Growth rates are significantly reduced among fetuses with trisomies 13,18 and with triploidy (Fig 29.4) Other sonographic method for detecting aneuploid fetus include abnormal fetal heart rate at 10–14 weeks, absent nasal bone, faccio maxillary angle, intracranial translucency, umbilical cord thickness and wide iliac angle By combining maternal age, nuchal translucency and heart rate, 83% fetuses with trisomy 21 were detected7 (Figs 29.5A and B) CHAPTER 29 / Ultrasonography and Birth Defects 483 Figures 29.3A to E: Measurement of nuchal translucency in the first trimester Figure 29.4: Measurement of crown-rump length Second Trimester Nuchal Fold Excessive soft tissue in the back of the neck is known to be a feature of newborns with Down’s syndrome Callen and colleagues8 described the use of thickened nuchal fold as a sonographic marker for Down’s syndrome in 1985 They showed that out of fetuses with Down’s syndrome had a nuchal thickness of equal to or greater than mm This measurement is done using the transverse section of the fetal head angled posteriorly to include the cerebellum and the occipital bone The measurement is made outside the occipital bone to the outer skin edge This measurement has remained the most sensitive and specific single marker for the mid trimester detection of Down’s syndrome Figures 29.5A and B: (A) Nasal bone; (B) Absent nasal bone Major Anomalies Infants with trisomy 21 have a 50% incidence of heart defects, most commonly ventricular septal defects and common atrioventricular canal Other major anomalies include ventriculomegaly, cerebellar hypoplasia, duodenal atresia, hydrops, omphalocele and limb anomalies.8 Femur length: Individuals with trisomy 21 are of short stature and have small femur and humerus.8 Absent nasal bone: Fetuses with absent nasal bone (Figs 29.5A and B) are associated with an increased risk of Down’s syndrome Mild fetal pyelectasis (Fig 29.6) was associated with an increased risk of Down’s syndome Crane and Gray defined pyelectasis as an anteroposterior diameter of the renal pelvis equal to or greater than mm.9 Nyberg and colleagues were the first to demonstrate that hyperechoic bowel (Fig 29.7) is associated with 484 Section / Obstetrics Figure 29.6: Fetal pyelectasis Figure 29.8: Echogenic intracardiac focus an otherwise low-risk patient, fetal karyotyping is unwarranted Minor Markers Figure 29.7: Echogenic mass in the small bowel Down’s syndrome There is also an increased risk of cystic fibrosis among fetuses with this sonographic finding, and parental allele testing for cystic fibrosis carrier status is recommended to evaluate this risk.10 The echogenic intracardiac focus (EIF) (Fig 29.8) has been seen among normal fetuses for many years and was considered a normal variant till 1994 Brown, Roberts and Miller in a case report showed that mineralization of the papillary muscle was associated with trisomy 21 in one of three fetuses.11 Lehman and colleagues were the first to report the association of EIF with trisomy 13 Several investigators have suggested that the association between an EIF and chromosomal abnormalities is low enough that, in the absence of other findings in Anomalies of the pelvic bones, particularly the iliac wings is associated with Down’s syndrome Children with Down’s syndrome have a wider lateral span of the iliac wing than normal children It is known among pediatricians and geneticists that infants with Down’s syndrome have brachycephaly and frontal lobe shortening An attempt is made to evaluate the use of this feature in detecting second-trimester fetuses with Down’s syndrome The transverse cerebellar diameter was evaluated as a possible marker for Down’s syndrome Other possible markers for the prenatal detection of Down’s syndrome have been put forth, including abnormal fetal heart rate patterns, abnormally shortened ear length, flat facies, clinodactyly, sandal gap great toe and the simian crease of the palm Trisomy 13 (Pateau syndrome): The incidence of trisomy 13 is in 5,000 births and it is the most severe of the three autosomal trisomies that can lead to live-born infants The fetal anomalies most commonly seen with these fetuses include abnormalities of the brain, face, extremities and heart In particular holoprosencephaly is a common finding that is invariably associated with severe midline facial defects, including hypotelorism, cyclopia, midline clefts, microophthalmia and absence of the nose Other intracranial anomalies that can be seen with trisomy 13 include microcephaly, abnormal posterior fossa, agenesis of corpus callosum and ventriculomegaly In addition, approximately 40% fetuses CHAPTER 29 / Ultrasonography and Birth Defects with trisomy 13 have echogenic intracardiac focus More than 90% of these fetuses have cardiac defects Abnormalities of the limbs include polydactyly and radial aplasia Other major defects include neural tube defects and anterior wall abdominal defects Thirty percent of affected fetuses have enlarged echogenic kidneys, similar to polycystic kidneys Placental abnormalities such as partial mole also have been described with trisomy 13.12,13 Triploidy: Triploidy is a syndrome that results from three sets of chromosomes yielding 69 chromosomes Most triploid conceptions end in spontaneous abortion When the extra set of chromosome arises from the maternal side, the placenta is small and senescent, and there is severe early intrauterine growth restriction When the extra set of chromosome arises from the paternal side, the placenta is large, full of echolucency and often associated with a partial mole.14 Usually the fetuses with triploidy have multiple congenital abnormalities of particularly every organ system Characteristically, they also have first trimester onset intrauterine growth restriction They also give rise to an unusual appearance of a very thin body with almost an normal sized head Fetal malformations associated with triploidy include early onset intrauterine growth retardation, facial anomalies such as hypertelorism, micrognathia and microphthalmia, brain anomalies such as ventriculomegaly, Dandy-Walker malformation, agenesis of corpus callosum, holoprosencephaly and meningomyelocele Affected fetuses also have thickened nuchal lucency/cystic hygroma, heart defects, renal anomalies, clubbed feet, single umbilical artery and oligohydramnios Most helpful of all in the specific diagnosis of triploidy is the syndactyly of the third and fourth digit of the hand, recognizable sonographically Turner’s syndrome: Turner’s syndrome is a chromosomal anomaly due to the loss of one sex chromosome, resulting in a 45X karyotype The missing chromosome is usually paternal and the syndrome is not related with maternal age In most cases conceptions with Turner’s syndrome are spontaneously aborted, some fetuses may persist into the second trimester with severe lymphatic abnormalities These fetuses have large cystic hygromas that are typically septated but clear Hydrops, pleural effusion, ascites and edema of all body parts is seen Mosaicism for Turner’s syndrome is more likely to result in live births and these individuals are often not diagnosed until puberty They suffer from sexual infantilism and short stature 485 In general, half of fetuses with Turner’s syndrome have cardiac anomalies and 19% have renal anomalies.15 Trisomy 18 (Edward’s syndrome): Trisomy 18 have an incidence of out of 10,000 live births and is associated with multiple severe structural abnormalities that mostly involve the heart, extremities, face and brain Affected fetuses are often miscarried or die in utero.16 Structural abnormalities associated with trisomy 18 involve abnormal cisterna magna and Dandy-Walker syndrome Affected fetuses can also have myelomeningoceles and ventriculomegaly Limb abnormalities include preaxial upper limb reduction and clenched hands with overlapping index fingers Second-trimester fetuses with trisomy 18 tend to have strawberry shaped skull, cerebellar deviation beyond two standard deviation below the mean, rocker bottom feet, clubbed feet, single umbilical artery and renal anomalies such as hydronephrosis Gastrointestinal tract anomalies include omphalocele and diaphragmatic hernia The triad of polyhydramnios, growth restriction and abnormal hand posturing is highly predictive of trisomy 18 in third trimester Umbilical cord cysts have also been associated with an increased incidence of trisomy 18 Choroid plexus cysts are present in approximately one-third of fetuses with trisomy 18 USG EXTRA FETAL EVALUATION Liquor Amnii Quantity • The measurement of the amniotic fluid can be done either by a single pocket measurement or the four quadrant approach amniotic fluid index (AFI) The AFI is easily reproducible and more accurate (Table 29.3) • Fetal swallowing and urinary flow are the primary regulators of amniotic fluid So abnormalities of these systems cause oligohydramnios (decreased liquor amnii) (Table 29.4) or polyhydramnios (increased liquor amnii), which can be indirect signs for detecting anomalies Amniotic bands • Whenever it is seen that the amniotic bands in the uterine cavity are traversing the gestational sac, one should be careful of evaluating whether any fetal part is impinged upon by these bands causing limb reduction defects or any other external anomaly of 486 Section / Obstetrics the cranium, face, anterior abdominal wall or spine (Fig 29.8) • Isolated ventricular dilatation • Tumors Umbilical Cord Cerebellum Number of Vessels This is evaluated for following parameters: • Cerebellar transverse diameter • Superior and inferior cerebellar vermis • Communication between fourth ventricle and cisterna magna • There should be two arteries and one vein in the umbilical cord • Whenever a single umbilical artery is diagnosed, a careful search for anomalies should be done especially of chromosomal abnormalities, major cardiac defects, holoprosencephaly, anterior abdominal wall defects and skeletal deformities With no other anomaly detected, continuation of pregnancy can be thought of • In a 2D ultrasound look for the rail-track appearance (Fig 29.9) to assess for number of vessels • On color flow mapping it is easy to see for two arteries and one vein but whenever in doubt always look for the hypogastric arteries adjacent to the urinary bladder to evaluate whether there are two arteries or not Cisterna Magna This is evaluated for following parameters: • Posterior fossa cyst • Depth Nuchal Skin This is observed for following parameters: • Thickness • Septation • Generalized hydrops Fetal Orbits and Face Origin and Insertion ULTRASONOGRAPHY FOR FETAL MORPHOLOGY EVALUATION The following parameters are observed: • Hypo or hypertelorism • Lens • Lips • Nostrils • Ears Choroid Plexus Fetal Spine This is evaluated for the following abnormalities (Fig 29.9): • Cysts • Hydrocephalus This is observed for following parameters: • Soft tissues • Longitudinal • Coronal • Axial • Ossification centers • Origin in respect to anomalies is important to differentiate between omphalocele and gastroschisis Fetal Thorax In this following parameters are observed: • Ribs • Diaphragm • Echotexture of lung • Lung length • Masses • Cardiothoracic ratio Fetal Heart Figure 29.9: Gray scale appearance of the umbilical cord The parameters observed for are as under: • Situs CHAPTER 29 / Ultrasonography and Birth Defects • • • • • • Size Rate Rhythm Configuration Connections Tumors • • • • 487 Ocular diameter Interocular distance Binocular distance Foot length Fetal Abdomen ULTRASOUND TECHNOLOGY AND ADVANCEMENT IN SCREENING Gastrointestinal Is Routine Screening Justified? • • • • • • Screening to be justified should fulfill many criteria; the procedure should be safe, reliable, reproducible, easily available and cost effective For a population which is at risk an ultrasound scan is justified but in developing countries like India where still almost half of our pregnant women have no access to a proper antenatal care, a routine ultrasound currently may not be practically feasible test for screening even though its utility and efficacy are beyond doubt.2 Stomach Duodenum Small bowel Large bowel Omentum Mesentery Pancreas Spleen Hepatobiliary • Liver • Gall bladder Genitourinary • Kidneys • Urinary bladder • Genitalia Fetal Skeleton The skeleton is observed for following parameters: • Cranium • Mandible • Clavicle • Spine • Extremities Fetal Biometry Following parameters are observed in fetal biometry: • Biparietal diameter • Occipitofrontal distance • Head perimeter • Abdominal perimeter • Femoral length • Humeral length • Nuchal skin • Cerebellar transverse diameter • Cisterna magna depth • Width of body of lateral ventricle Is Incidence of Fetal Malformation High Enough to Merit Screening? According to Heinonen (1977) approximately 150,000 children are born with malformations annually in USA where almost 100% pregnant women have antenatal care and institutional deliveries In developing countries the incidence is higher due to inability for detection, screening and more exposure to teratogens Is Outcome of Undetected Congenital Malformations Detrimental Enough to Warrant a Routine Screening? Out of an incidence of around 6% congenital malformations almost half (2.5%) are lethal, life threatening and have a major cosmetic defect.17 Major congenital defect mostly manifest in fetal intrauterine life (ultrasound detectable), sometimes in fetal life (ultrasound suspicion) and occasionally in childhood (ultrasound undetectable) Some experts question the need of routine prenatal ultrasound screening for this reason.18 Fetal medicine is still not advanced to treat potential life-threatening conditions like open neural tube defects and cardiac defects where death is the expected outcome after delivery Occasionally, these defective babies survive and are severely handicapped Diagnosis of such conditions during pregnancy can give the couple an option of termination Current technology enables detection of over 60% fetal malformations.19,20 488 Section / Obstetrics Can a Prenatal Diagnosis of Anomalies Ease Emotional Pain? An antenatal diagnosis of congenital anomaly whether lethal, life threatening or even less serious can still help couples and doctors to prepare themselves for the challenge to come.21 There is a definite benefit of screening for both patients and physicians Usually a normal ultrasound scan is good news for the expecting parents because of the relative low prevalence of anomalies in general population and also relative low incidence of false-positive results by ultrasound.22 If the ultrasound screening is positive for anomaly then the counseling and discussion of all options can be done and choice left open to the expecting parents.23 Is Prenatal Ultrasound Screening Cost Effective? It is difficult to assess cost-effectiveness of screening and there are only a few studies on this Certain costs like purchase, maintenance of equipments, salary of well trained technicians and doctors can be assessed and is expensive.24 Emotional costs of family disorganization and suffering cannot be calculated Because of the many options for handling anomalies available from termination to major plastic surgery it is again difficult to assess whether it is cost effective to detect an anomaly Helsinki ultrasound trial (1996)25 has shown that second-trimester screening for anomalies by ultrasound is cost effective How Does Prenatal Anomaly Scan for Screening Influence Infant Health? Ultrasound screening is not primary prevention because it cannot prevent the anomaly It can only detect the problem and if the anomaly is lethal, it gives the expecting parents an option to terminate pregnancy— secondary prevention Also in many cases, severe but curable defects (cardiac) can be managed by treating newborn without delay, if the pediatric surgery unit is prepared Expertly performed prenatal ultrasound screening and autopsy reports correlate and provide accurate information.26 What are the Options After Diagnosis of Congenital Malformations? The options for managing congenital malformation pregnancy have to be discussed with the expecting parents and the final choice lies with the parents A team of specialists should provide all information and counseling This team should consist of obstetrician, sonologist, geneticist, neonatologist, pediatric surgeon and a psychologist Options selected depend on severity of the anomaly and can be as mentioned below: • Termination of pregnancy • Intrauterine treatment • Maternal transport to tertiary care center • Premature delivery • Immediate specialized neonatal care • Additional diagnostic tests • Extensive monitoring Alternatives or Adjuncts to Ultrasound? There are various blood tests like maternal serum alpha fetoprotein (MSAFP), triple test, quadruple tests and many interventional procedures like chorionic villus sampling (CVS) and amniocentesis, cordocentesis and fetal biopsy which can help in direct karyotyping and chromosomal analysis of the fetus These procedures and techniques are expensive, not easily available and also carry a procedure related risk of miscarriage Noninvasive magnetic resonance imaging (MRI) is definitely not a cost-effective method for screening Ultrasound advances have made this technology for screening an ideal test because it is: • Relatively low cost • Ease to perform • Real-time display • Acceptable to all • Widely available • Accurate • Safe • Reproducible • Available as office investigation • Can now be applied from late first trimester also.27 How Long Does it Take? A primary screening ultrasound examination is a systemic analysis of fetal growth and fetal morphology system and will take 10–20 minutes to scan The screening will stop if everything appears normal in all significant organs and structures Depending on image quality, maternal obesity, gestational age, type of anomaly, color Doppler or 3D scan still the total scan duration rarely exceeds 30 minutes For subtle defects or solitary markers or inexperienced sonologists a second opinion scan might be required by an expert which will take another 30 minutes CHAPTER 29 / Ultrasonography and Birth Defects What Does a Prenatal Ultrasound Scan Show? Depending on the gestational age the defects can be seen and identified, e.g nuchal translucency in first trimester, duodenal atresia, gastrointestinal defects, neural tube defects and some cardiac defects in second trimester.28 When we don’t see the expected image of the fetus we suspect a defect Sometimes, we have to look for soft markers and signs of chromosomal anomalies, e.g banana sign, lemon sign, etc Ultrasound can also pick up functional abnormalities and abnormal fetal biophysical profile and abnormal fetal behaviors 489 In another study on 170,000 pregnant women, 4,000 malformed fetus were detected with a sensitivity of 61%.31 What Counts as Success in Genetic Counseling? Whenever anomaly is detected for some people, the abortion and termination of pregnancy is a matter of course response and no ethical dilemma arises However, among certain religions groups objections to termination pose an ethical dilemma Advances in Fetal Surgery Abnormal Fetal Activity • • • • Rapid uncoordinated fetal movements Fetal arrhythmia Fetal vomiting Fetal GI stenosis This option is still a research tool and there is an ethical aspect that many of these fetal surgical procedures are still experimental and of uncertain value and to give or not to give this option to couples carrying a malformed pregnancy is a dilemma When Should a Screening Prenatal Scan be Done? Are 3D and 4D Scans for Screening Useful or Gimmicks? Nicolaides has suggested a 11–14 weeks scan for screening for chromosomal anomalies, trisomy 21 by looking at the nuchal translucency and nasal bone ossification.28 Other workers have suggested addition of biochemical markers 29 The detection rate for trisomies varies from 80–89% with a false-positive rate of 5% by using multiple markers study in first trimester scan (11–14 weeks) A second-trimester anomaly scan should be done between 18–22 weeks and a detailed fetal echocardiography and color Doppler uterine artery and ductus venosus should be done Third-trimester screening should not be delayed more than 32 weeks gestation and is mainly done for growth and color Doppler studies for hypoxia detection Late anomaly screening for GI and urinary tract anomaly is usually done at 32 weeks Ideal time for ultrasound screening for each and every gravida should be a monthly ultrasound but as this is not practical and feasible, at least each pregnancy should have two scans one 11–14 weeks scan and one second-trimester scan.30,31 There is now an increasing availability of 3D ultrasound The benefits of 3D and 4D ultrasound techniques are now a matter of debate The 3D and 4D screening help in maternal fetal bondage and also help in recognition and better confirmation of certain anomalies like cleft lips, polydactyly, micrognathia, malformed ears, club foot, vertebral malformations and other exterior surface anomalies Development of transvaginal scanning (TVS) 3D probes have further enhanced its value in early diagnosis of malformations Ultrasound: How Sensitive it is for Malformation Detection? In a major study on 500,000 cases about 11,000 (2.2%) were found to be malformed fetus with a range of sensitivity from 14–80% (mean 45.5%) Reassurance Scans—How Reassuring? It was proposed by Prof Stuart Campbell that a 3D routine scan is to reassure the parents and to rule out anomalies, but also criticized these as entertainment scans used and marketed for unprecedented profit particularly after 4D ultrasound SCREENING METHODS AND TESTS Maternal and Fetal Screening Tests Noninvasive and Invasive Introduction: There are many screening tests conducted on the mother or directly on the fetus/pregnancy products, which may be invasive or noninvasive These tests vary in their effectiveness, i.e the detection rate or the sensitivity and specificity of the test The best 490 Section / Obstetrics way to assess which is the best screening test would be to fix the false-positive rate and compare the detection rate of various tests Noninvasive Tests: These tests are performed on maternal blood (serum screening) and by an ultrasound scan Detection of any abnormal level of hormones in maternal blood or abnormal measurement of fetal parameters increases the relative risk for the fetus to have a chromosomal defect The ‘detection rate’ of any test depends upon following the highest standards of practice in both, scanning and as well as in the laboratories Hence, the ‘efficacy’ of the test largely depends upon the laboratory performing the blood tests and the operator performing the fetal scan Invasive Tests: These tests are largely done to confirm a suspected diagnosis of genetic disease and in a few cases for fetal infections Test samples are taken from the placenta (chorionic villous sampling, CVS), amniotic fluid (amniocentesis) or fetal blood (cordocentesis) These tests involve inserting a needle into the pregnancy sac to retrieve the sample This requires a high level of expertise as it carries a risk of miscarriage of the entire pregnancy, which largely depends upon the operator skills Screening Tests Versus Diagnostic Tests It is important to know and understand the difference between screening test and a diagnostic test • Screening tests help to evaluate the risk for certain birth defects, but they cannot diagnose a birth defect Screening tests are noninvasive and pose no risk to mother or baby Diagnostic tests, such as aminocentesis, cordocentesis and chorionic villus sampling (CVS), are highly accurate at diagnosing or ruling out birth defect However, these tests are invasive and may pose a very small risk of miscarriage Application of Various Maternal and Fetal Screening Tests to Pregnant Women Screening test such as an ultrasound can be performed at any stage of the pregnancy However, most screening tests, particularly blood tests are not performed after 22 weeks; firstly because the efficacy of the tests declines steeply after that period and secondly in most countries late termination of pregnancy is restricted The best detection rate for the tests can be obtained when performed in the particular window period of gestations The following tests are the most widely performed CONCLUSION With improved technology, in particular the development of high frequency transvaginal ultrasound probes and its increased acceptance with the patients, it has become possible to examine the detailed fetal anatomy even in the late first trimester and early second trimester The new panorama of normal embryological development is possible with 3D ultrasound and with computers handling the pre- and postprocessing of the ultrasound images gives us a future insight into the future of technology being applied to achieve a better understanding of early human developments and its defects ACKNOWLEDGMENTS The authors are grateful to Prof Asim Kurjak, Dr Ashok Khurana, Dr JP Shah, Dr Kuldeep Singh and Dr P Radha Krishna for their inputs REFERENCES Heinonen OP, Sloane D, Shapiro S Birth defects and drugs in pregnancy Littleton MA: PSG Publishing; 1977 pp 4101 Hill LM, Breckle R, Gehrking WC The prenatal detection of congenital malformations by ultrasonography Mayo Clin Proc 1983;58(12):805-26 Benacerraf Beryl R Ultrasound of fetal syndromes Philadelphia: Churchill Livingston; 1998 p 328 Callen PW, et al Ultrasonography in Obstet and Gynecol, 4th edition Philadelphia, PA: WB Saunders; 2000 pp 3867 Pandya PP, Santiago C, Sjniders RJM, et al First Trimester fetal nuchal translucency Curr Opin Obstet Gynecol 1995;7(2):95-102 Schemmer G, Wapener RJ, Johnson A, et al First trimester growth patterns of aneuploid fetuses Prenat Diag 1997;17(2):155-9 Hyett JA, Noble PL, Snijders RJM, et al Fetal heart rate in trisomy 21 and other chromosomal abnormalities at 10–14 weeks of gestation Ultrasound Obstet Gynecol 1996;7(4): 239-44 Rotmensch S, Liberati M, Bronstein M, et al Prenatal sonographic findings in 187 fetuses with Down’s syndrome Prenat Diag 1997;17(11):1001-9 Rotmensch S, Mandell J, Estroff JA, et al Fetal Pyelectasis: a possible association with Down syndrome Obstet Gynecol 1992;79(5 Pt 1):770-2 10 Nyberg DA, Resta RG, Mahony BS, et al Fetal hyperechogenic bowel and Down’s syndrome Ultrasound Obstet and Gynecol 1993;3:330-3 CHAPTER 29 / Ultrasonography and Birth Defects 11 Brown DL, Roberts DJ, Miller WA Left ventricular echogenic focus in the fetal heart: pathologic correlation J Ultrasound Med 1994;13(8):613-6 12 Jones KL Smith’s recognizable patterns of human malformations, 5th edition Philadelphia: WB Saunders; 1997 p 30 13 Lehman CD, Nyberg DA, Winter TC III, et al Trisomy 13 Syndrome: prenatal US findings in a review of 33 cases Radiology 1995;194(1):217-22 14 Rubenstein JB, Swayne LC, Dise CA, et al Placental changes in fetal triploidy syndrome J Ultrasound Med 1986;5:54550 15 Shepard J, Bean C, Bove B, et al Long term survival in a 69 XXY triploid male Am J Med Genet 1986;25(2):307-12 16 Droste S, FitzSimmons J, Pascoe-Mason J, et al Growth of linear parameters in trisomy 18 fetuses Am J Obstet Gynecol 1990;163(1 Pt 1):158-61 17 Snijders RJM, Nicolaides KH Ultrasound markers for fetal chromosomal defects New York, NY:Parthenon Publishing Group;1996 pp 63-120 18 Grandjean H, Larroque D, Levi S, et al The performance of routine ultrasonographic screening of pregnancies in the Eurofetus study Am J Obstet Gynecol 1999;181(2):446-54 19 Levi S Cost effectiveness of antenatal screening for fetal malformation by ultrasound: an evaluation of antenatal mass screening by ultrasound for the diagnosis of birth defects (1990-1993) Report to the European Commission, European Union, contract MR4*-0225-B;1995 20 McNeil TF, Torstensson G, Nimby G Psychological aspects of screening In: Kurjak S (Ed) Textbook of perinatal medicine London, England: Parthenon Publishing; 1998 pp 717-29 21 Levi S Screening for congenital malformations by ultrasound In: Kurjak S (Ed) Textbook of perinatal medicine 22 23 24 25 26 27 28 29 30 31 491 London, England: Parthenon Publishing; 1998 pp 587609 Reed KL Why (not) obstetric ultrasound? An observation on uncertainty Ultrasound Obstet Gynecol 1996;8(1):1-2 Leivo T, Tuominen R, Saari-Kemppainen A, et al Costeffectiveness of one-stage ultrasound screening in pregnancy: a report from the Helsinki ultrasound Trial Ultrasound Obstet Gynecol 1996;7(5):309-14 Cheschire NC, Reitnauer PJ A comparative study of prenatal diagnosis and perinatal autopsy J Ultrasound Med 1994;13(6):451-6 Salvesen KA, Eik-Nes SH Is ultrasound unsound? A review of epidemiological studies of human exposure to ultrasound Ultrasound Obstet Gynecol 1995;6(4):293-8 Rosendahl H, Kivinen S Antenatal detection of congenital malformations by routine ultrasonography Obstet Gynecol 1989;73(6):947-51 Nicolaides KH, Azar G, Byrne D, et al Fetal nuchal translucency: ultrasound screening for chromosomal defects in 1st trimester of pregnancy BMJ 1992;304(6831):867-9 Spencer K, Souter V, Tul N, et al A screening program for trisomy 21 at 10–14 weeks using fetal nuchal translucency, maternal serum free beta-human chorionic gonadotropin and pregnancy associated plasma protein-A Ultrasound Obstet Gynecol 1999;13(4):231-7 Levi S, Montenegro N Eurofetus: an evaluation of routine ultrasound screening for the detection of fetal defects: aims and method In: Chervenak F, Levi S (Eds) Ann NY Acad Sci 1998;847:103-17 Clarke A What counts as success in genetic counseling J Med Ethics 1993;19(1):47-9 Langham MR, E Reiger KM Advances in fetal surgery Surgery Annual 1994;26:193-226 .. .Donald School Textbook of Ultrasound in Obstetrics and Gynecology Donald School Textbook of Ultrasound in Obstetrics and Gynecology THIRD EDITION Editors Asim Kurjak MD PhD Professor and. .. Obstetrics and Gynecology University Medical School of Insubria, Varese, Italy viii Donald School Textbook of Ultrasound in Obstetrics and Gynecology Vincenzo D’Addario Department of Obstetrics and Gynecology, ... Aleksandar Ljubic School of Medicine University of Belgrade, and Institute for Obstetrics and Gynecology Clinical Center of Serbia Belgrade, Serbia Kazuo Maeda Department of Obstetrics and Gynecology